1. Organic Polymer ChemistryBY
Dr. Ghulam Abbas

2. Some Definitions
Polymer: From the Greek, poly + meros, many parts. Any long-chain molecule synthesized by bonding together single parts called monomers.
Monomer: From the Greek, mono + meros, single part. The simplest necessary unit from which a polymer is synthesized.
Plastic: A polymer that can be molded when hot and retains its shape when cooled.

3. Thermoplastic: A polymer that can be melted and
Conti…
Thermoplastic: A polymer that can be melted and
molded into a shape that is retained when it is cooled
(recycle) e.g. Nylon, polycarbonate (eyeglass lens),
polyethylene (shampoo bottles).
Thermoset polymer: A polymer that can be molded
when it is first prepared but, once it is cooled,
hardens irreversibly and cannot be remelted.
Examples are synthetic fibers, print roller, duroplast.

4. Polymerization Reactions
• Polymerization = Reaction to convert monomers to a polymer. There are two types of polymerization reaction;
1- Step-Growth Polymerization (Condensation Polymers): It
applies to monomers with functional groups such as:
-COOH, -COOR, -COOOC-, -COCl, -OH, -NH2, -CHO,
-NCO, epoxy.
Chain Polymerization (Addition Polymers): It applies to monomers having double bonds or ring structure.
• Both classes of reaction can lead to the formation of either linear polymers or polymer networks. It only depends on the number of reactive entities per monomer.

5. Step-Growth Polymerization
Basic Reactions
• Condensation: coupling reaction with loss of small molecule
Example:
CH3-NH2 + HOOC-CH2-CH CH3-NH-CO-CH2-CH3 + H2O
Amine + Acid Amide + Water
• Addition: coupling reaction without loss of small molecule
CH3-N=C=O + HO-CH2-CH CH3-NH-CO-O-CH2-CH3
Isocyanate + Alcohol Urethane

6. Step-Growth Polymers
Step-growth polymerization: A polymerization in which chain growth occurs in a stepwise manner between difunctional monomers.
Five types of step-growth polymers:
1- Polyamides
2- Polyesters
3- Polycarbonates
4- Polyurethanes
5- epoxy resins

7. Polyamides Nylon 6-6 Nylon 6-6 (from two six-carbon monomers).
During fabrication, nylon fibers are cold-drawn to
about 4 times their original length, which increases
alignment, crystallinity, tensile strength, and
stiffness.

8. NYLON PRODUCTS

9. Polyamides, Nylon 6
Nylons are a family of polymers, the two most widely used of which are nylon 6-6 and nylon 6. Nylon 6 is synthesized from a six-carbon monomer.
Nylon 6 is fabricated into fibers, brush bristles,
and tire cords.

10. Polyamides, Kevlar Kevlar is a polyaromatic amide (an aramid).
Cables of Kevlar are as strong
as cables of steel, but only
about 20% the weight.
Kevlar fabric is used for
bulletproof vests, jackets,
and raincoats.

11. Polyesters, PET
Mylar films
Poly (ethylene terephthalate), abbreviated PET or PETE, is fabricated into Dacron fibers, Mylar films, and plastic beverage containers.
Dacron fibers

12. Polycarbonates, Lexan
To make Lexan, an aqueous solution of the sodium salt of bisphenol A (BPA) is brought into contact with a solution of phosgene in CH2Cl2.

13. Polycarbonates, Lexan
Lexan is a tough transparent polymer with high impact and tensile strengths and retains its shape over a wide temperature range.
It is used in sporting equipment, such as
bicycle, football, and snowmobile helmets
as well as hockey and baseball catcher’s
masks. It is also used in the manufacture of safety and unbreakable windows.

14. Polyurethanes A urethane, or carbamate, is an ester of carbamic
acid, H2NCH2COOH.
They are most commonly prepared by treatment of an
isocyanate with an alcohol.
Polyurethanes consist of flexible polyester or
polyether units alternating with rigid urethane
units. The rigid urethane units are derived from a
diisocyanate.

15. Epoxy Resins
Epoxy resins are materials prepared by a polymerization in which one monomer contains at least two epoxy groups.
Epoxy resins are produced in forms ranging
from low-viscosity liquids to high-melting
solids.

16. Epoxy Resins
prepared by treating one mole of bisphenol A with two moles of epichlorohydrin.

17. Chain-Growth Polymers
Chain-growth polymerization:
A polymerization that involves sequential addition reactions, either to unsaturated monomers or to monomers possessing other reactive functional groups.
Reactive intermediates in chain-growth polymerizations include radicals, carbanions, carbocations, and organometallic complexes.

18. Chain-Growth Polymers
We concentrate on chain-growth polymerizations of ethylene
and substituted ethylenes.
Several important polymers derived from ethylene and
substituted ethylenes, along with their most important
Uses are shown as;

19. Polyethylenes

20. Radical Chain-Growth
Among the initiators used for radical chain-growth
polymerization are diacyl peroxides, which decompose
On mild heating.

21. Radical Chain-Growth
Another common class of initiators are azo compounds,
Which also decompose on mild heating or with absorption
of UV light.

22. Radical polymerization of a substituted ethylene. Chain initiation:
Radical Chain-Growth
Radical polymerization of a substituted ethylene.
Chain initiation:
Chain propagation:

23. Radical Chain-Growth
Chain termination

24. Elastomeric Materials
Common characteristics;
Large elastic elongation (i.e. 200%)
Can be stretched and then immediately return to their original length when the load was released.
Elastomers are sometimes called rubber or rubbery materials.
The term elastomer is often used interchangeably with the term rubber.
Elastomers are usually thermosets (requiring vulcanization) but may also be thermoplastic.

25. Natural Rubber Rubber tree (Hevea Braziliensis)
Natural rubber is obtained by drying a latex rubber (milk in which the butter fat component is suspended in water salution)
High temperature stability – cooking the crude natural rubber with sulphur (vulcanization)
Vulcanization creates crosslinking between rubber molecules
Natural rubber is highly elastomeric (elongation 1000% for vulcanized natural rubber).
Compared to other elastomeric materials, natural rubber shows higher tensile strength, high tear strength, high resilience, resistance to wear, etc

26. Polyisoprene structure
The most frequent causes of death are congenital heart defects and respiratory infections.
Cis-poliisoprena
(Hevea rubber)
Trans-poliisoprena
(Gutta percha)

27. Polybutadiene has just two hydrogen attached to the C-C double bond.
Butadiene Rubber (BR)
Synthetic rubber
Repeating units of both have a backbone of four carbon atoms including C-C double bond
Polybutadiene has just two hydrogen attached to the C-C double bond.
Absence of methyl group in polybutadiene results in strength & tear strength than would polyisoprena.
Information included demographic information, codes for underlying cause of death, and up to 20 disorders that are listed on death certificates.

28. Styrene Butandiene Rubber (SBR)
Information included demographic information, codes for underlying cause of death, and up to 20 disorders that are listed on death certificates.

29. Polymer Stereochemistry
There are three alternatives for the relative configurations of stereocenters along the chain of a substituted ethylene polymer.

30. Polymers Applications
Polymers (or plastics as they are also called) are known to have good insulating properties.
Polymers are one of the most used materials in the
modern world.  Their uses and application range from containers to clothing. They are used to coat metal wires to prevent electric shocks. 

31. Conclusion For conductance free electrons are needed.
Conjugated polymers are semiconductor materials while doped polymers are conductors.
The conductivity of conductive polymers decreases with falling temperature in contrast to the conductivities of typical metals, e.g. silver, which increase with falling temperature.
Today conductive plastics are being developed for many uses.

32. THE END Shield for computer screen against electromagnetic
"smart" windows
radiation
smart" windows
Solar cell
Light-emitting diodes